scholarly journals Antibacterial Action Mechanisms of Honey: Physiological Effects of Avocado, Chestnut, and Polyfloral Honey upon Staphylococcus aureus and Escherichia coli

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1252 ◽  
Author(s):  
Patricia Combarros-Fuertes ◽  
Leticia M. Estevinho ◽  
Rita Teixeira-Santos ◽  
Acácio G. Rodrigues ◽  
Cidália Pina-Vaz ◽  
...  

Numerous studies have explored the antibacterial properties of different types of honey from all around the world. However, the data available describing how honey acts against bacteria are few. The aim of this study was to apply a flow cytometry (FC) protocol to examine and characterize the primary effects of three varieties of honey (avocado, chestnut and polyfloral) upon physiological status of Staphylococcus aureus and Escherichia coli cells to reveal their antibacterial action mechanisms. The effects of honey samples on membrane potential, membrane integrity, and metabolic activity were assessed using different fluorochromes, in a 180 min time course assay. Time-kill experiments were also carried out under similar conditions. Exposure of S. aureus and E. coli to the distinct honey samples resulted in physiological changes related to membrane polarization and membrane integrity. Moreover, honey induced a remarkable metabolic disruption as primary physiological effect upon S. aureus. The different honey samples induced quite similar effects on both bacteria. However, the depth of bacteria response throughout the treatment varied depending on the concentration tested and among honey varieties, probably due to compositional differences in the honey.

2019 ◽  
Vol 7 (8) ◽  
pp. 258 ◽  
Author(s):  
Patricia Combarros-Fuertes ◽  
Leticia M. Estevinho ◽  
Rita Teixeira-Santos ◽  
Acácio G. Rodrigues ◽  
Cidália Pina-Vaz ◽  
...  

Several studies have explored the antimicrobial properties of manuka honey (MkH). However, the data available regarding antibacterial action mechanisms are scarcer. The aim of this study was to scrutinize and characterize primary effects of manuka honey (MkH) upon the physiological status of Staphylococcus aureus and Escherichia coli (as Gram-positive and Gram-negative bacteria models, respectively), using flow cytometry (FC) to reveal its antibacterial action mechanisms. Effects of MkH on membrane potential, membrane integrity and metabolic activity were assessed using different fluorochromes in a 180 min time course assay. Time-kill experiments were carried out under the same conditions. Additionally, MkH effect on efflux pumps was also studied in an E. coli strain with an over-expression of several efflux pumps. Exposure of bacteria to MkH resulted in physiological changes related to membrane potential and membrane integrity; these effects displayed slight differences among bacteria. MkH induced a remarkable metabolic disruption as primary physiological effect upon S. aureus and was able to block efflux pump activity in a dose-dependent fashion in the E. coli strain.


2020 ◽  
Vol 2 (2) ◽  
pp. 61-68
Author(s):  
Agnina Listya Anggraini ◽  
Ratih Dewi Dwiyanti ◽  
Anny Thuraidah

Infection is a disease caused by the presence of pathogenic microbes, including Staphylococcus aureus and Escherichia coli. Garlic (Allium sativum L.) has chemical contents such as allicin, alkaloids, flavonoids, saponins, tannins, and steroids, which can function as an antibacterial against Staphylococcus aureus and Escherichia coli. This study aims to determine the antibacterial properties of garlic extract powder against Staphylococcus aureus and Escherichia coli. This research is the initial stage of the development of herbal medicines to treat Staphylococcus aureus and Escherichia coli infections. The antibacterial activity test was carried out by the liquid dilution method. The concentrations used were 30 mg/mL, 40 mg/mL, 50 mg/mL, 60 mg/mL and 70 mg/mL. The results showed that the Minimum Inhibitory Concentration (MIC) against Staphylococcus aureus and Escherichia coli was 40 mg/mL and 50 mg / mL. Minimum Bactericidal Concentration (MBC) results for Staphylococcus aureus and Escherichia coli are 50 mg/mL and 70 mg/mL. Based on the Simple Linear Regression test, the R2 value of Staphylococcus aureus and Escherichia coli is 0.545 and 0.785, so it can be concluded that there is an effect of garlic extract powder on the growth of Staphylococcus aureus and Escherichia coli by 54.5% and 78.5%. Garlic (Allium sativum L.) extract powder has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.


Author(s):  
Bing Han ◽  
Xiaoyu Han ◽  
Mengmeng Ren ◽  
Yilin You ◽  
Jicheng Zhan ◽  
...  

Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environment-friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H 2 O 2 -Ag + ) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900 and Salmonella typhimurium SL 1344. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against S. aureus were found to be 0.014 % H 2 O 2 -3.125 mg/L Ag + , while 0.028 % H 2 O 2 -6.25 mg/L Ag + for both E. coli and S. typhimurium . Results of the growth curve assay and time-kill trial suggest that the HSC could inhibit the growth of the tested bacteria, as 99.9 % of viable cells were killed following treatment at the 1 MIC for 3 h. Compared with Oxytech D10 disinfectant (0.25 % H 2 O 2 -5 mg/L Ag + ), the HSC exhibited better antibacterial efficacy at a lower concentration (0.045 % H 2 O 2 -10 mg/L Ag + ). The mechanism of antibacterial action of HSC was found including the disruption of the bacterial cell membrane, followed by entry into the bacteria cell to reduce intracellular adenosine triphosphate (ATP) concentration, and inhibit the activity of antioxidases, superoxide dismutase (SOD) and catalase (CAT). The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.


2021 ◽  
Author(s):  
Davood Gheidari ◽  
Morteza Mehrdad ◽  
Saloomeh Maleki ◽  
Samanesadat Hosseini

Abstract With the increase of general knowledge and the advancement of science and technology, antibacterial substances were used more than antibiotics. In our current study, the antibacterial virtues of CFO/BiOI nanocomposite were investigated due to its high importance on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus. MIC, MBC , Disk Diffusion and IC50 tests Cefalotin (CF), Amoxicillin (AMX), Gentamicin (GM), Trimethoprim-sulphamethoxazole (SXT) and Ceftriaxone (CRO) antibiotics in concentration 30W, 10i, 10t , 25h and 30 were used to find the antibacterial properties of the synthesized nanocomposite, respectively. For the synthesis of nanocomposites polyethylene glycol (PEG) and sulfonic acid was used as a solvent. It is noteworthy that the synthesis was performed by heat dissolution method without the presence of surfactant. Also, various techniques such as X-Ray Diffraction(XRD), Scanning Electron Microscope (SEM), High resolution mapping and Energy Dispersive X-ray spectroscopy (EDAX) have been used to determine the properties of produced nanocomposites. SEM test results showed that the formed nanoparticles were globular and their size was limited area of 22 to 34 nm. The results showed CFO / BiOI nanocomposite exhibits strong significant biological activity against Bacillus cereus. The results of MBC (Minimum Bactericidal Concentration) and MIC (Minimum Inhibition Concentration) tests for CFO/BiOI nanocomposites on bacteria were examined in the range of 0.12-0.48 mg/ml and 0.06 to 0.24 mg/ml respectively. According to the results, the minimum IC50 value was determined at a concentration of 0.061 mg/ml. On the other hand, the most resisting and susceptible bacteria in this method were Pseudomonas aeruginosa and Bacillus cereus, respectively. These findings are identical to those of a prior study on CoFe2O4 nanoparticles antibacterial properties. MBC of the nanocomposites, 50 µl from all the tubes that showed no obvious bacterial growth were distributed on BHI agar plates and incubated for 24 h at 37 ◦C. The MBC endpoint is defined as the lowest concentration which killed 98% of the bacterial population.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1782
Author(s):  
Amir M. Ashrafi ◽  
Pavel Kopel ◽  
Lukas Richtera

The electrochemical redox behavior of three trinuclear Ni(II) complexes [Ni3(abb)3(H2O)3(µ-ttc)](ClO4)3 (1), [Ni3(tebb)3(H2O)3(µ-ttc)](ClO4)3·H2O (2), and [Ni3(pmdien)3(µ-ttc)](ClO4)3 (3), where abb = 1-(1H-benzimidazol-2-yl)-N-(1H-benzimidazol-2-ylmethyl)methan-amine, ttcH3 = trithiocyanuric acid, tebb = 2-[2-[2-(1H-benzimidazol-2-yl)ethylsulfanyl]ethyl]-1H-benzimidazole, and pmdien = N,N,N′,N″,N″-pentamethyldiethylenetriamine is reported. Cyclic voltammetry (CV) was applied for the study of the electrochemical behavior of these compounds. The results confirmed the presence of ttc and nickel in oxidation state +2 in the synthesized complexes. Moreover, the antibacterial properties and cytotoxic activity of complex 3 was investigated. All the complexes show antibacterial activity against Staphylococcus aureus and Escherichia coli to different extents. The cytotoxic activity of complex 3 and ttcNa3 were studied on G-361, HOS, K-562, and MCF7 cancer cell lines. It was found out that complex 3 possesses the cytotoxic activity against the tested cell lines, whereas ttcNa3 did not show any cytotoxic activity.


2014 ◽  
Vol 875-877 ◽  
pp. 87-90 ◽  
Author(s):  
Chutimon Satirapipathkul ◽  
Tanakan Chatdum

The film-forming potential of isolate of seed polysaccharide fromCassia fistulawas investigated. Increasing the glycerol concentration in the film increased elongation at break, film solubility and water vapor permeability but decreased tensile strength (TS). The film impregnated with the acetone extract ofAtractylodes lanceawas assessed for inhibition ofEscherichia coliandStaphylococcus aureus. The obtained results showed that the films exhibited antibacterial activity against both bacterial strains. Disc-diffusion assay revealed that the film resulted in a larger inhibition zone around the film onStaphylococcus aureusthan it did onEscherichia coliat the same extract concentrations (0.1 to 0.9 wt %). It can be seen that the film has satisfactory physical and antibacterial properties.


2020 ◽  
Vol 840 ◽  
pp. 293-299
Author(s):  
Poedji Loekitowati Hariani ◽  
Muryati Muryati ◽  
Muhammad Said ◽  
Salni Salni

Nano-hydroxyapatite was synthesized by coprecipitation method and tested its antibacterial properties. Nano-hydroxyapatite was synthesized using CaO precursors from snakehead (Channa striata) fish bones and (NH4)2HPO4. The synthesis was carried out with temperature variations of 30, 60, 80, and 100 °C. Antibacterial activity was determined using two types of bacteria, namely gram-positive and gram-negative. The XRD spectra show that the highest peak is hydroxyapatite synthesized at a temperature of 100 °C. Hydroxyapatite produced from various synthesis temperatures has the size of nanoparticles in the range 37.32-49.27 nm. The nano-hydroxyapatite functional groups are characterized using FTIR, the analysis indicate the presence of OH, CO32‒ and PO43‒. The molar ratio Ca/P is obtained of 1.71 approaching theoretical hydroxyapatite of 1.67. The resulted nano-hydroxyapatite has significant antibacterial properties to Escherichia coli and Staphylococcus aureus.


2001 ◽  
Vol 2 (1) ◽  
Author(s):  
Ana Marcia De Matos Volpato ◽  
Ester De Moura Rios ◽  
Marilis Dallarmi Miguel ◽  
Paulo Cesar Sander ◽  
Obdúlio Gomes Miguel

A atividade antimicrobiana de Calendula officinalis L. (Asteraceae) já foi cientificamente comprovada em outros países. O objetivo deste trabalho foi avaliar a atividade antibacteriana de C. officinalis cultivada no Paraná - Brasil, nas condições de extração etanólica 50%, com filtração e partições sucessivas com hexano, diclorometano, acetato de etila e butanol, frente a cepas Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228 e Bacillus cereus, pela técnica da difusão em meio sólido por cavidade e posteriormente pelo método de diluição em placa. Os resultados demonstraram que algumas frações do extrato inibiram as bactérias gram-positivas, com atividade frente a Staphylococcus e Bacilos e inexiste em gram negativas, indicando que o princípio ativo responsável pela atividade antibacteriana observada possa ser isolado a partir das frações Hexânica e DCM nas condições de extração propostas neste trabalho. Abstract The Calendula officinalis L. (Asteraceae) antimicrobial action has already been scientifically proved in other countries. The aim of this study was to assess the antibacterial action of the Callendula officinalis which is grown in Paraná - Brasil, under extraction conditions at ethanol 50%, with filtration and successive partitions with hexane, dichloromethane, ethyl acetate and butane, contrasting with strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228 and Bacilus cereus, by the difusion technique in solid media by cavity and afterwards by the plaque dilution method. The results showed that some fractions of the extract inhibited the gram-prositive bacteria, with activity in contrast with Staphylococcus and Bacillus and non-existing in gram-negative, also indicating that the active ingredient responsible for the antibacterial action observed can be isolated from the Hexanic and DCM fractions under the extraction conditions proposed in this study.


2012 ◽  
Vol 534 ◽  
pp. 78-81
Author(s):  
Ting Wei Hu ◽  
Shao Yun Shan ◽  
Shi Mei Yang ◽  
Li Hong Jiang ◽  
Ya Ming Wang ◽  
...  

Polyaniline(PANI)/TiO2 nanocomposites are successful synthesized by one step-interfacial polymerization method. Morphologies and structures of the nanocomposites are characterized using SEM, FTIR, and XRD. The antibacterial properties of PANI/TiO2 nanocomposites on Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Bacillus megateriu and Bacillus cereus are tested. The effect of molar ratio of aniline and tetrabutyl titanate on structures and antibacterial properties are also been explored. The results show that the content of tetrabutyl titanate has a obvious influence on structure and morphologies of the nanocomposites. PANI/TiO2 nanocomposites have antibacterial properties especially on Staphylococcus aureus and Escherichia coli, which shows a best antibacterial property when the molar ratio of aniline to tetrabutyl titanate is 3:2.


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